<svg xmlns="http://www.w3.org/2000/svg" 
     xmlns:xlink="http://www.w3.org/1999/xlink" 
     xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" 
     onload="boom();">
     
<script type="text/javascript">

function boom()
{
  document.getElementById("b").style.position = "absolute";
  document.getElementById("a").style.color = "green";
}

</script>

<defs>
  <g id="a"><xul:listbox/></g>
</defs>

<g id="b"><use xlink:href="#a"/></g>

</svg>
